The present invention relates to an electric motor including busbars serving as relay members that relay electrical connection between a driving circuit for controlling a driving current that leads to coils that make a rotor rotated by an electromagnetic force, and the coils, and further relates to an electric pump unit including the electric motor.
As an electric motor that has busbars used as relay members that relay electrical connection with an external driving circuit, etc., an electric motor described in, for example, JP-A-2005-27413 is known. This electric motor includes three-phase circuit lead wires (busbars) electrically connected to three coils that surround a rotor and constitute U, V, and W phases, respectively. The three-phase circuit lead wires are fixedly welded to internal terminals, are electrically connected to three harness slots provided in output terminal blocks that are adjacent to one another in the axial direction of the rotor via three-phase-circuit output bolts, and are electrically connected with three harnesses (wiring lines for connection) pulled out from the external driving circuit, etc. in the respective harness slots.
In the above-described conventional electric motor, the three-phase-circuit lead wires serving as the busbars connected to the coils that constitute the phases are connected with the harness slots provided in the output terminal blocks, via the internal terminals and three-phase circuit output bolts that are separate connecting members other than the three-phase circuit lead wires.
For this reason, in addition to the three-phase circuit lead lines (busbars), the internal terminals and the three-phase-circuit output bolts are needed for connection from the coils to the external driving circuit. Thereby, a connection system from a coil that constitutes each phase to an external driving circuit in an electric motor becomes complicated, and the number of parts increases. Further, lightness and compactness of the electric motor will be hindered due to the output terminal blocks having the harness slots, and the space occupied by the output terminal blocks.